Conventional examples of electronic parts mounting methods for automatically insert an electronic part with a lead wire into the insertion hole of a substrate will be described referring to FIGS. 1 to 5.
In FIG. 1, an electronic parts mounting apparatus for automatically inserting an electronic part 5 with lead wires 6a, 6b into the insert holes 2a, 2b of a substrate 2 comprises an insert head section 1, an anvil section 4 and an XY table section 3. The insert head section 1 and the anvil section 4 are so positioned above and below the substrate 2 as to sandwich it, and vertically moved symmetrically in accordance with the inserting position of parts. The XY table section 3 holds the substrate 2 with the insert holes 2a, 2b for inserting the lead wires 6a, 6b and moves in the XY direction to position the aforesaid insert holes 2a, 2b to the aforesaid part insert positions.
First, the electronic part 5 equipped with the lead wires 6a, 6b retained at fixed intervals on the tapes 9a, 9b as shown in FIG. 2(a) is supplied to the aforesaid insert head 1.
Next, with the aforesaid insert head section 1, as shown in FIG. 2(b), electronic parts 5 are separated one by one from the tapes 9a, 9b and are lowered while retained at the insert guide sections 7a, 7b as shown in FIG. 3. The front ends of the lead wires 6a, 6b are pushed into the aforesaid insert holes 2a, 2b of the substrate 2, positioned on the XY table section 3, with bushers 8a, 8b and those of the aforesaid lead wires 6a, 6b are inserted into the aforesaid insert holes 2a, 2b. In parallel with this, the aforesaid anvil section 4 rises from below the aforesaid substrate 2 toward the aforesaid insert holes 2a, 2b so as to come up to a position symmetrical to the aforesaid insert head 1. The nails 4a, 4b of this anvil section 4 bend the front ends of the aforesaid lead wires 6a, 6b inward. After the completion of this operation, the insert head section 1 rises and the anvil section 4 lowers.
As mentioned above, electronic parts 5 are mounted onto the substrate 2 in the state shown in FIG. 5.
Then, the insert head section 1 rises and the anvil section 4 lowers. Until the insert guide sections 7a, 7b come down while holding the next electronic part, the XY table section 3 moves to position the insert holes 2a, 2b for inserting the lead wires 6a, 6b of the following part 5 to the aforesaid part insert positions.
As shown in FIG. 4, however, electronic parts 5 are mounted on the top face of the substrate 2, while electronic parts 10 are mounted on the bottom face of the substrate 2. Accordingly, the control proceeds by such interlocking that the XY table 3 begins to move the substrate 2 after the front ends of the insert guide 7a, 7b rise up to a higher position H6 than the height h6 of an electronic part 5 and the front ends of the nails 4a, 4b of the anvil section 4 lowers down to a lower position H10 than the height h10 of an electronic part 10.
With the background art, to simplify the control of this interlocking, the movement of the XY table 3 is so interlocked that the front ends of the insert guide 7a, 7b and the nails 4a, 4b of the anvil section 4 are kept so apart from the substrate 2 as not to make contact with the largest part to be mounted with the electronic parts mounting apparatus and to allow the XY table 3 to be movable regardless of the presence of electronic parts.
With an electronic parts mounting apparatus, however, an attempt to promote the mounting efficiency by shortening the mounting cycle time for vertical reciprocal movement of the insert head section 1 and the anvil section 4 requires it to shorten the positioning movement of the XY table 3 also in accordance with the aforesaid mounting cycle time. Meanwhile, an actual electronic parts mounting apparatus has a problem that the movement of the XY table 3 requires more time than the mounting cycle time because it moves the substrate 2 for positioning, namely, the shortening effect of the aforesaid mounting cycle time is reduced by such restriction of the moving time of the XY table 3.